#define _CRT_SECURE_NO_WARNINGS 1 
#include<stdio.h>
int average(int x, int y)
{
	return x + (y - x) / 2;
}
int main()
{
	int a = 0;
	int b = 0;
	scanf("%d %d", &a, &b);
	int age = average(a, b);
	printf("%d", age);

	return 0;
}